The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Along with the enhancement of modern management and the conception of temporal efficiency, people at different places expect to have both video and audio communications with each other. As a result, videoconferencing systems emerged and have been developing gradually. The videoconferencing system, which is based upon color video camera techniques, optical communication technologies, multimedia computer control technologies, single-chip control technologies, large-scale video matrix switching technologies as well as audio conference technologies, implements interaction and exchange of video and audio information between two or more individuals located at physically distinct locations. The videoconferencing system improves the quality of conference, saves the expense and enhances the efficiency of conference.
A videoconferencing system commonly consists of a main site and multiple sub-sites. In each site there is a terminal and all the terminals for the conference are controlled by a multipoint control unit (MCU), and are connected by satellite networks or computer networks. The main site is the control center of a videoconferencing system. The console used as the primary control equipment as well as the image and voice assigning or switching equipment are all deployed in the main site. To control the process of videoconference effectively, the console of the main site needs to know which of the sub-sites has enrolled. Generally speaking, a connection problem, a failure of the terminal, inappropriately configured parameters, quit of the sites or switch-off of the terminal may all lead to the un-enrollment of a sub-site. The un-enrolled site, which occupies the port resources, will have an impact on the proper process of the videoconference. If the videoconferencing system is an operating system leased by the client, it will further affect the accounting operation.
However, in the existing videoconferencing systems, the H.230, H.243, H.323 or H.245 protocols are generally used to control the conference. During the process of controlling the conference with these protocols, only the list of the enrolled sites can be transmitted among the terminals of the sub-sites, the MCU and the console of the main site. The operator of the console in the main site can only handle the enrolled sites. As the list of the un-enrolled sites is not provided, the user is unable to get this information about the un-enrolled sites. The user has to contact the console to know which site has not enrolled, and for this purpose, the user has to call the console by itself, which wastes the time of the user and affects the efficiency of the whole videoconferencing system. After getting the list of the un-enrolled sites, the user has to record the information about the list, which is inconvenient for the user, especially when the number of the un-enrolled sites is large. Besides, the user can't handle the un-enrolled sites via the terminal directly, but only handle the un-enrolled sites via the console, which affects the flexibility and the convenience in controlling the whole videoconferencing system.